package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Autowired
    private RedisIdWorker redisIdWorker;

    @Resource
    StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
    private IVoucherOrderService proxy;

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new voucherOrderHandler());
    }
    private class voucherOrderHandler implements Runnable{

        @Override
        public void run() {
            while(true){
                try {

                    //1、获取订单里面的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    handleVoucherOrder(voucherOrder);
                    //2、创建订单
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }
            }
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1获取用户
        Long id = voucherOrder.getId();
        //2创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + id, stringRedisTemplate);
        RLock lock = redissonClient.getLock("order:" + id);
        //3获取锁
        boolean isLock = lock.tryLock();
        //4判断获取锁成功
        if(!isLock){
            //获取锁失败
            log.error("不允许重复下单");
            return ;
        }
        //获取代理对象（事务）
        try {
            proxy.createVoucherOrder(voucherOrder);
        }finally {
            //释放锁
            lock.unlock();
        }
    }

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //1、执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        //2、判断结果是否为0
        int r = result.intValue();
        if(r != 0){
            //2.1 不为0
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        // 把下单信息保存到阻塞队列中
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.1 订单id
        Long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //2.2 用户id
        voucherOrder.setUserId(userId);
        //2.3 优惠券id
        voucherOrder.setVoucherId(voucherId);
        //2.4 放入阻塞队列
        orderTasks.add(voucherOrder);

        //3获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4 返回订单id
        return Result.ok(orderId);

    }


    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();
        Long voucherId = voucherOrder.getVoucherId();
            //查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            //判断订单是否存在
            if (count > 0) {
                log.error("用户已经购买过一次");
                return;
            }
            //5、扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId).gt("stock", 0)
                    .update();
            if (!success) {
                log.error("库存不足");
                return;
            }

            save(voucherOrder);


        }


    //    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1、查找优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//
//        //2、判断秒杀是否开始
//        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
//            // 秒杀尚未开始
//            return Result.fail("秒杀尚未开始");
//        }
//
//        //3、判断秒杀是否结束
//        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
//            // 秒杀已经结束
//            return Result.fail("秒杀已经结束");
//        }
//
//        //4、判断库存是否充足
//        if (voucher.getStock() <1) {
//            return Result.fail("库存不足");
//        }
//        Long id = UserHolder.getUser().getId();
//        //创建锁对象
//        //SimpleRedisLock lock = new SimpleRedisLock("order:" + id, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("order:" + id);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        //判断获取锁成功
//        if(!isLock){
//            //获取锁失败
//            return Result.fail("不允许重复下单");
//        }
////        synchronized (id.toString().intern()){
//            //获取代理对象（事务）
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return  proxy.createVoucherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
////        }
//
//    }

}
